This book is possibly the first study to show effects of biogas digested slurry based-biochar and digested liquid on agriculture and environment. The readers may find it interesting how digested slurry could be handled easily and utilized in more industrial way. The readers can find how methane production and consumption potential, and methanogenic archaeal diversity could be different in paddy soils. This book also shows the effects of varying concentration of biochar on greenhouse gases production and crop yield in waterlogged and aerobic environment. The readers could also see how the method of applying digested liquid affects greenhouse gases evolution, soil chemical properties and crop yield. This book also indicates that methanogenic archaeal community remain unchanged in one cropping season of paddy under various amendments application. However, soil chemical and microbial properties, methane evolution and paddy plant biomass varied under different treatments. I wish this book could be helpful to researchers who are looking to make biofuel production more efficient; as proper utilization of biofuel byproducts will decrease the overall cost production of biofuels.